Feeler thread gauge



Dec. 24, 1957 G. JAKUBIAK 2,817,153

FEELER THREAD GAUGE Filed Dec. .21, 1953 I Gfeorya LmZZZZ dzf/ ENTOR BY W.

ATTORNEYS United States Patent FEELER THREAD GAUGE George Jaknbiak, Barberton, Ohio Application December 21, 1953, Serial No. 399,251

1 Claim. (Cl. 33-199) This invention relates to a feeler thread gauge.

It is a principal object of this invention to provide a feeler thread gauge of the kind to be more particularly described hereinafter to check and determine the threads of a work piece for use in a home machine shop or the like to determine the proper gauge of the threads being cut or otherwise formed on the work piece.

It is another object of this invention to provide a feeler thread gauge of this kind designed for controlling, trying and finding the size of the threads in the process of being cut in job shops or small home shops and the like.

It is a further object of this invention to provide a novel feeler thread gauge of this kind to make a complete check of the thread cut at any time in the process of cutting threads on a work piece from the first to the last pass of the cutting machine without changing the machine or operation set up.

It is still another object of this invention to provide a feeler thread gauge of this kind having a separate gauge pin as required by the machine operator or inspector for the various thread pitches and threads encountered to assure the operator that the product will meet all the requirements before it is permitted to leave the machine shop.

It is yet a further object of this invention to provide a feeler thread gauge of this kind engageable at any and all check points of a thread to enable a sure test of a standard fit of the threads of the work piece.

Other and further objects and advantages of the invention will be hereinafter described and the novel features thereof defined in the appended claim.

In the drawings:

Fig. 1 is a top plan view of a key ring with a plurality of feeler gauges, shown in side elevation, on the key ring.

Fig. 2 is a perspective view of one of the feeler gauges removed from the key ring.

Fig. 3 is a longitudinal section of a work piece with a feeler gauge, constructed according to an embodiment of this invention, disposed between a pair of adjacent threads on the work piece.

Fig. 4 is a transverse section of the work piece with the feeler gauge and the fiat micrometer anvil in engagement with the threads of the work piece.

Referring more specifically to the drawings the numeral designates generally a key ring on which a plurality of thread gauges 11 are loosely engaged for their selection to gauge the threads of a given piece of work.

A plurality of rods designated generally as 12, 12' and 12" are shown in Fig. 1 of the drawings and a selected one of the rods may be used for determining the pitch or gauge of the thread on a piece of work. A tab 13 being flat in configuration holds each one of the rods 12, 12 and 12" and a separate tab may be used for each of the thread gauges to be carried on the key ring 10.

Each of the tabs 13 is provided with a plurality of laterally extending, longitudinally aligned brackets 14 having openings 14' therethrough through which one end 2,817,153 I Patented 13cc. 1957 of the selected rod, as the rod 12, may be engaged and the other of the bracketsbeing engageable about the rod in spaced relation to the first mentioned bracket 14.

Each of the brackets 14 is provided with an opening 14' through which the selected gauge rod may be extended and an opening 15 for attachment of the gauges to a supporting ring.

The tab 13 is also provided with indicia 16 near one end thereof and in spaced relation to the rod carried by the individual tab.

A work piece 17 is provided having threads 18 about the periphery thereof and each of the threads 18 is formed with flat sides or flanks 19 inclined at a suitable angle as illustratively of 60 relative to the axis of the work piece 17.

A flat apex or crest is formed on the upper edge of each of the threads 18 and there is provided a fiat portion or root 21 on the work piece 17 between each of the threads 18 as clearly shown in Fig. 3 in the drawings.

For determining the gauge of the threads 18 on the work piece 17, one of the gauge rods as the gauge rod 12, is positioned between a pair of adjacent threads 18 with the circumference of the cylindrically formed elongated gauge rod 12 in engagement with the flat edges or sides of the threads 18.

In order to ascertain that the threads 18 on the work piece 17 are proper a thread gauge 12 is inserted between the adjacent threads on the work piece and a micrometer anvil 22 is positioned on the upper end or flat apex of the adjacent threads and will bear against the circumference of the thread gauge being used.

As an example, a work piece of this kind provided with a 60 thread and having eight teeth per inch, the use of one particular type of gauge rod, as the gauge rod 12 will determine that the formation of the threads 18 is correct.

With a feeler thread gauge of this kind a check may be made at any point on the circumference of the work piece when it is desired to gauge the thread being cut. When a thread is cut from a first pass to the last and complete pass, there is always a check point for trial without changing the machine or the operation set up. This is a definite advantage over the prior used feeler thread gauges not only to the operator but also the processor or manufacturer who must be sure that his product will meet all the requirements before it leaves his shop.

While the specific details of one embodiment of this invention have been herein shown and described, the invention is not confined thereto as changes and alterations may be made without departing from the spirit and scope thereof as defined in the appended claim.

I claim:

A feeler thread gauge for triangular threads of a screw of the type having flat crests and roots, including a pinrality of different diameter circular wire feelers, a selected feeler being adapted to seat between adjacent flanks of the thread in tangential relation, whereby a micrometer anvil placed upon the flat crest of a thread will seat in tangential relation to the top of a feeler of proper diameter when the thread gauge is accurate, a flat tab for each feeler, longitudinally aligned spaced brackets having aligned bores therethrough on each tab, each feeler extending through the bores of a tab and being secured therein, indicia on each tab denoting the size of the associated feeler, each tab having an opening therein, and a ring passed through the opening of each tab for holding said plurality of feelers in association for selec tion of a desired feeler for thread gauge measurement.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Publication, American Machinist, page 805, May 21,

1931. g Publication, Supplement to Screw Thread Standards Ross Dec 23 1952 O 1 15, 1949. Useful definitions, Pierce Apr 1956 pages 35-37; Illustration of standard 60-degree thread u forms, pages 46, 47. 

